1. Field of the Invention
The present invention relates to a method for controlling the orientation of short fibers in a short fiber-reinforced article or body which is formed from a mixture of short fibers (including, e.g., whisker) and solvent (including, e.g., organic binder, inorganic binder and water).
2. Description of the Prior Art
Attempts have been made previously to orientate short fibers and thus their fiber axes in a given direction in a short fiber shaped article or body for effective fiber-reinforcement of the composite material, and known orientating methods include using extrusion or rolling (see Japanese Patent Publication No. 1561/75) and one employing magnetism (see Japanese Patent Application Laid-open No. 95909/73).
However, the former method is to mechanically orientate a short fiber by use of dies or the like and hence, is accompanied by the following problems. It is possible to provide the orientation of the short fiber parallel to an extruding direction, but it is impossible to effect a control to incline the short fiber relative to the extruding direction or the like. Moreover, the short fiber is liable to be folded and damaged. In addition, although it is possible by using magnetism to orientate the short fiber in a surface layer of the short fiber shaped body which comes into contact with the dies or the like, it is difficult to orientate the short fiber present in the interior of the short fiber shaped body. On the other hand, the latter method is also accompanied by the problems that it is difficult to effect the aforesaid control, it is not suitable for a short fiber having no magnetic properties, and its extent of application is limited.